Fukushima Daiichi nuclear power plant No. 2, cooling function all stopped

On March 12Explosion occurred at Unit 1 of Fukushima Daiichi Nuclear Power PlantFollowing on, today at 11:01Hydrogen explosion occurred at Fukushima Daiichi nuclear power plant Unit 3It was announced that the cooling function of the adjacent Unit 2 was also stopped following Units 1 and 3.

Details are as below.
Cooling function stopped at Fukushima Daiichi Unit 2: Society: YOMIURI ONLINE (Yomiuri Shimbun)

According to the announcement by NISA and the information given to Fukushima prefecture, it seems clear that the function to cool down the nuclear reactor of Fukushima Daiichi nuclear power plant 2 was all lost at 13:25.

Since the pressure inside the containment vessel continues to be high, we are considering ways to ensure safety by releasing air to the outside.

This is Fukushima Daiichi nuclear power plant No. 2


2011/03/14 16: 00
Current affairs dot com: Unit 2 also stops cooling function = cooling water level, decreasing trend - Fukushima No. 1 nuclear power plant

According to a contact from TEPCO to Fukushima Prefecture, the nuclear reactor cooling function stopped at 1:25 pm on Fukushima No. 1 nuclear power plant No. 2. The water level of the cooling water tends to decrease. (2011/03 / 14-15: 22)

Fukushima No. 1 Unit 2 cooling function lost NHK News

According to the Nuclear and Industrial Safety Agency of Japan's Ministry of Economy, Trade and Industry, the Fukushima Daiichi Nuclear Power Station Unit 2 at TEPCO in Fukushima Prefecture has equipment for circulating water to cool down the nuclear reactor, , I found out that it was all lost at 1:25 pm. In Unit 2, since the pressure inside the containment vessel containing the nuclear reactor continues to be high, in the future we will consider ways to ensure safety by releasing air from the containment to the outside It is.

2011/03/14 16: 06
Asahi.com (Asahi Shimbun): Cooling function of Unit 2 Fukushima Daiichi Nuclear Power - Society

According to a report entered in the Fukushima Prefecture Disaster Countermeasure Headquarters, the cooling function of the nuclear reactor was lost at TEPCO Fukushima Daiichi nuclear power plant No. 2 at around 1:25 pm. For this reason, the water level of the nuclear reactor tends to decline.

According to the explanation of TEPCO Fukushima office, the water level in the reactor core declined from about 300 cm to about 240 cm in the afternoon from 0:30 PM to 1:30 PM.

For this reason, TEPCO decided that the cooling function of the reactor had been lost at 1:25 pm. I reported the situation to Fukushima Prefecture at 1:38 pm. A person in charge of the TEPCO Fukushima office said, "I would like to cope with not to be like Units 1 to 3. I would like to take action earlier, such as measures to prevent venting, seawater injection, hydrogen explosion."

Although the circulation of water to cool the reactor so far was functioning, Unit 2 seems to have stopped moving for some reason.

2011/03/14 16:18
At a press conference by Chief Cabinet Secretary Chief Cabinet Secretary, it was revealed that preparations for seawater injection are proceeding for Unit 2, where the cooling system stopped. In addition, for the Unit 3, where the seawater injection was interrupted by the explosion, we are also making efforts to restart seawater injection at an early stage.

2011/03/14 16:23
First nuclear power plant Unit 2 emergency notification NHK News

According to the Ministry of Economy, Trade and Industry's Nuclear and Industrial Safety Agency, the function of circulating water and cooling the reactor at the Fukushima Daiichi Nuclear Power Station Unit 2 at TEPCO in Fukushima Prefecture is lost at 1:25 pm I understood that. For this reason, TEPCO made a so-called "Article 15 Notification" to inform the government of the "emergency" based on the Nuclear Emergency Preparedness Measures Law,

On Unit 2, on 11th of this month when the earthquake occurred, it was judged that all of the "emergency diesel generators" necessary to cool down the nuclear reactor could not be used and the ability to continue cooling was not sufficient, TEPCO has issued "Article 15 Notification" to notify of "emergency". In Unit 2, after that, even though there was no electricity, we used steam to circulate the water and continued to cool the reactor, but the temperature inside the containment vessel containing the nuclear reactor increased and it became impossible to cool down That means that. Tokyo Electric Power Company is examining ways to ensure safety even at Unit 2 in the future as there is a possibility of hydrogen explosion as with Unit 1 and Unit 3.

Nuclear safety and NISA interview


It is said that the water level of the cooling water dropped as the cooling function of Unit 2 stopped.


2011/03/14 19: 25
Nuclear fuel of Unit 2 is exposed from the water surface NHK News

In Unit 2 of Fukushima Daiichi Nuclear Power Plant, we circulated water using a moving device using steam, and continued to cool the reactor, but the surrounding temperature became high and it became impossible to cool down. Because of this, TEPCO made a so-called "15 notification" to inform the government of the "emergency" based on the law at 1:30 pm on the assumption that all cooling functions were lost. According to TEPCO, the height of the water that cooled the nuclear reactor sharply dropped, and the fuel rod began to be exposed to the surface of water at 5 PM. For this reason TEPCO rushed work to cool the nuclear reactor with seawater and assumed that there was a possibility that hydrogen explosion, which seems to have occurred in Unit 1 and Unit 3, may also occur in Unit 2, and a hole is made in the wall of the reactor building We are considering measures to open and release hydrogen out.